<h1>Reciprocal tariffs deadline threatens trade partners as US readies warning letters, risking higher import duties.</h1> The administration will send warning letters indicating that reciprocal tariffs may be imposed on designated trading partners after a temporary pause ends; the legal impact depends on which partners are included, the tariff rates assigned, and the chosen effective dates. A postponed effective date could allow negotiations or extensions, while immediate enforcement would trigger compliance obligations and trade adjustments for affected importers and exporters.